In Microsoft Office Excel 2007/2010, you open an .xls file that is located on a network share and then save it with a different name. When you do this, the modified date of the original .xls file is not reset to the original modified date and time as expected.
Note This issue does not occur when the .xls file is located on a local disk or when the file has an .xlsx, an .xlsm, or an .xlsb file format.
This issue occurs because Excel 2007/2010 writes the name of the current user to the header of the file when you open an Excel workbook. This process is required so that other users receive the "file in use" notification. The operating system then updates the last modified date.
To work around this issue, follow these steps:
Right-click the file, and then click Copy.
In the Windows Explorer window, right-click in a blank space, and then click
Right-click the file, click Rename, and then type the new name for the file.
Double-click the file to edit it in Excel.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
826741 Excel changes Modified date and time when you open the workbook